Quality of life, cortisol blood levels and exercise in older adults: results of a randomized controlled trial

Introduction: Cortisol plays a central role in the stress response; while high stress can determine physical and psychological impairment, moderate stress, with a mild increase in cortisol level, may have a positive effect on coping and physical performance. This trial attempted to determine whether cortisol levels were associated with Quality of Life (QoL) in a sample of elderly subjects undertaking an exercise program. Methods:42 subjects aged ≥65 years were randomlyassigned in a 1:1 fashion either to a vigorous physical activity (VAG: N=21) or to a postural gimnastic group (PGG: N=21). Differences between the two groups in QoL (on SF-12), and blood cortisol levels were assessed by ANOVA at different times. Results:In both the VAG and PGG, cortisol levels rose at the end of the trial, with statistically significant differences as compared to the baseline. QoL at the end of the trial was higher than in the national normative sample. Cortisol and QoL in both groups decreased slightly 12 weeks after the end of the trial (T2); however, only in the VAG did the difference from the initial level remain statistically significant. At T1 and T2, subjects with higher SF-12 scores were found in subsamples in both groups with cortisol levels moderately increased (between 200 and 300 mg/ml). Conclusion:In a sample of elderly subjects undergoing two different kinds of exercise, a better perception of Quality of Life was associated with a moderate, non-pathological increase in cortisol. The results need to be confirmed by trials on larger samples.